Boosting UV photodetector performance with copper-doped NiO nanoflake thin films

Abstract

In this report, the pristine and copper-doped nickel oxide (NiO) nanoflakes were synthesized at ambient temperature on ITO substrate with different ratio of Cu dopant (0 %, 3 %, 6 %, and 9 %) via the successive ionic layer adsorption and reaction technique. The NiO:Cu nanoflakes' microstructure, surface morphology, composition analysis, optical characteristics, and UV photoconduction analysis were all thoroughly examined. XRD analysis verified the cubic structure occupying the space group (Fm3m) of NiO thin films to be free of any impurity phases. The bandgap values exhibit a decreasing trend with increasing doping concentration. The morphological investigations reveal that all samples show uniformly distributed nanoflakes grains without voids or defect structures. The prepared pure and Cu-doped NiO thin film photodetectors were examined via I-V characteristics and photo-sensing parameters. The results reveal that the 6 % Cu-doped NiO photodetector sample possesses higher photocurrent, improved responsivity of 28.1 × 10⁻² AW⁻¹, detectivity of 13.19 × 10⁹ Jones, and EQE of 75.13 %.